"We dove to the bottom of the Mariana Trench five times in 10 days, it had had two visits in 60 years before we went there," Vescovo said.

Tamara Stubbs

The submarine "Limiting Factor" is prepared at a drop point above the Mariana Trench.

The 'Five Deeps' expedition has already successfully reached the bottom of the Atlantic Ocean, Southern Ocean, Indian Ocean and Pacific Ocean. Vescovo is planning to complete his historic expedition in late August when he dives the Molloy Deep in the Arctic Ocean. The entire journey will be made into a Discovery documentary.

First, Vescovo will dive to the second deepest trench in the Pacific, the Tonga Trench, he says there is a slim chance it could actually be deeper than the Mariana Trench.

Diving isn’t Vescovo’s only passion-- he’s also a climber. Once he finishes his last dive in August, he will be the only person to ever summit the highest mountain on each continent and go to the lowest point of each ocean. He will have been to the "roof of the world," Mt. Everest, and its’ floor, the Mariana Trench.

"I always had the urge to explore, even as a little kid," Vescovo said.